Process of making malleable-iron castings



Dec. 3, 19 's. 1,564,437

. w. J. MILES, JR

PROCESS OF HAKING MALLEABLS IRON CASTIN GS Filod Jan. 10, 1920 PatentedDec. 8, 1925.

UNIT D STATES WILLIAM J. MILES, JR,

OF MIDDLETOWN, OHIO.

PROCESS OF MAKING MALLEABLE-IBON CASTINGS.

Application filed January 10, 1929.

To all whom it may concern Be it known that I, WILLIAM J. Minus, J12, acitizen of the United States residing at Middletown, in the county ofButler and State of Ohio, have invented a new and useful Process of i lfaking hlalleablelron Castings, of which the following is aspecification.

This invention relates to processes for the manufacture of malleableiron castings.

The object of the invention is to provide a process which will yield thehighest quality of malleable iron at less cost and in less time than byother processes.

The invention will be best understood from a consideration of thefollowing detailed description taken in connection with the accompanyingdrawings forming part of this specification, with the understanding,however, that the invention is not confined to any strict conformitywith the showing of the drawings but may be changed and modified so longas such changes and modifications mark no material departure from thesalient features of the invention as expressed in the appended claims.

In the drawings Figure 1 is a perspective view showing a cupola and anair furnace, the latter being illustrated with its top removed;

Figure 2 is a sectional view showing one of the removable cover or roofsections of the air furnace in place on the walls thereof.

8 is a cupola, having a charging mouth 9 and a charging platform 10.This cupola is of well known construction used in all iron foundries andneeds no further description. An air furnace 11 is built adjacent thecupola with the spout (not shown) of the latter leading directly intothe air furnace. Figure 1 shows a single air furnace in connection withthe cupola, but obviously there may be several air furnaces used with asingle cupola.

The air furnace has a hearth 12 and an opening 13 which receives thespout of the cupola. This opening 13 is located well above the hearthand is shaped so that the molten iron falls in a comparatively finestream as-it passes from the cupola to the hearth of the air furnace. Adischarging vent 14 is provided on the opposite side of the hearth, bymeans of which the bath of metal may be run off when purified intoladles for the molding process. The air furnace has a fire chamber 18 atone end Serial No. 350,665.

and fines 16 at the other, which fines pass under the hearth and leadout to the stack 17. Passages 19, closed by doors, are provided in thewalls of the air furnace whereby the bath of metal may be rabbled atintervals. The top of the air furnace is closed by a plurality of coversections similar to that shown in Figure 2. When the lining is toberenewed or other repairs made, one or more of these cover sections areremoved.

The manner in which the above-described apparatus is used in my processwill now be described. a

Pig iron, along with a certain portion of sprue iron, malleable, steelscrap and the like, is charged into the cupola with the fuel inalternate layers. The blast through the tuyeres is then started, and themetal quickly melts. At short intervals the molten metal is allowed topass from the cupola to the hearth of the air furnace which it strikesin a fine stream. The air reaching the metal in this fine stream largelyremoves the impurities left in the metal after the melting in thecupola. The intense heat radiating from the walls and roof of the airfurnace enables the oxidation of the impurities in the molten metal tobe brought about more speedily. From time to time the metal may berabbled through the openings 19. When the metal is ready, it will bedrawn off through the discharge vent- 1 into ladles and teemed into themolds.

By first melting the iron in the cupola I save fuel and oxidation,because iron is melted quicker in a cupola than in an air furnace, andsince it melts quicker it does not have time to oxidize. A cupola ofgood efficiency will use one part of fuel to eight of metal; whereas thebest air furnace practice employs one part of fuel to four of metal;thus there is a great advantage in melting iron in a cupola.

However, the contact of the metal and fuel in a cupola makes metalpeculiarly liable to burning which gives rise to sluggish iron, castingsfull of pin holes and trouble in the anneal. So instead of dependingupon the cupola to accomplish the removal of all the impurities, I passthe molten iron before it has had time to become burned, directly intoan air furnace without coming in contactwith outside air in its passage.As the molten iron reaches the interior of the air furnace it falls in afine stream which,

with the air striking it, brings about the elimination of the silicon,phosphorus and sulphur.

Ordinarily, an air furnace while yielding a product of a high degree ofpurity has the disadvantage of using twice as much fuel as a cupola doesto meltthe same quantity of iron. In short, the cupola is eflicient formelting iron, the air furnace for purifying it. I combine the cupola andthe air furnace into an apparatus which utilizes the cupola to initiallymelt the iron and the air furnace to purify the product to the degreewhich is so desirable. use little fuel because the iron being pouredinto it in a molten condition only needs sufficient heat to keep itmolten and to eliminate the remaining few impurities. Thus a muchshorter time is required in the air furnace for the final purification.-

It is within the province'of my invention to employ a plurality of airfurnaces if necessary with a single cupola As is well known airfurnaces, even though of small size, may have a high efliciency.Inasmuch as continuous melting with a cupola gives the best results,it'may be desirable to pour metal continuously from a-cupola and useseveral airfurnaces in connection therewith so that while one airfurnace is being filled and a second one-is in the process of purifyingits bath, a third may be in condition to discharge its metal.

The air furnace willlV hat is claimed is 1. The process of refining ironin the manufacture of malleable iron castings which includes melting theiron in a cupola, and running the iron in a fine stream from the cupolainto an air furnace.

2. The process of refining iron in the mai'iufacture of malleable ironcastings which comprises melting the impure iron and removing certain ofthe impurities in a cupola, causing the molten iron to run from thecupola directly upon the hearth of an air furnace strikingthe same in afine stream, at the same time excluding the atmosphere from contact withsaid stream of molten iron.

3. The process of refining iron in the manufacture of n'ialleable iron-astings which consists in melting the impure iron and removing certainof the impurities in a cupola running the molten iron from the cupolainto an air furnace in a fine stream, said stream being out of contactwith the atn'iesphere while passing from the cupola to the air furnaceand falling upon the hearth of the air furnace while played upon by aircurrents, and removing the rest cf the impurities in the metal bath inthe air furnace.

in testimony that I claim the foregoing as my own I have hereto aflixedmy signature.

lVl'LLIAM J. MILES, J 1:.

